000200224 001__ 200224
000200224 005__ 20190509132510.0
000200224 0247_ $$2doi$$a10.5075/epfl-thesis-6326
000200224 02470 $$2urn$$aurn:nbn:ch:bel-epfl-thesis6326-4
000200224 02471 $$2nebis$$a10183890
000200224 037__ $$aTHESIS
000200224 041__ $$aeng
000200224 088__ $$a6326
000200224 245__ $$aFunctionalized Carbon Nanostructures from Oligoyne Carboxylates
000200224 269__ $$a2014
000200224 260__ $$bEPFL$$c2014$$aLausanne
000200224 336__ $$aTheses
000200224 502__ $$aProf. N. Marzari (président) ;
 Prof. H. Frauenrath (directeur) ;
 Dr C. Mattevi, 
 Prof. D. Schlüter, 
 Prof. F. Stellacci (rapporteurs)
000200224 520__ $$aFunctional nanostructured carbon materials, including two-dimensionally extended nanosheets, offer
 intriguing perspectives for applications in emerging technologies such as hydrogen storage, lithium
 storage, transition metal free catalysis, or solar absorbers. The preparation of such materials with
 a control over the structure formation and chemical functionalization would render them better
 processable and suited for tailored applications. In this context, the present thesis investigated
 a novel approach for the low-temperature, wet-chemical preparation of two-dimensional carbon
 nanostructures. Novel amphiphilic molecules with reactive oligoyne segments were envisioned as
 precursors that would self-assemble into defined aggregates and subsequently be carbonized under
 mild conditions while preserving the morphology and the embedded chemical functionalization.
 The foundation of this novel approach was the development of a reliable synthetic procedure for
 the preparation of the desired precursor molecules. To this end, we employed a palladium-catalyzed
 coupling protocol based on the Negishi reaction that allowed for the direct bond formation between
 two sp-hybridized carbons. We then followed a versatile linear synthetic strategy that allowed for
 the successful preparation of hexayne carboxylates on the multi-gram scale. In the course of our
 synthetic work, we encountered an unprecedented single-crystal-to-single-crystal dimerization that
 we carefully investigated by means of spectroscopy, X-ray analysis of crystalline specimen, as well
 as DFT computations. The dimerization provided the first synthetic access to unsymmetric 1,2-dibromoeneyne products and, thus, extended the scope of single-crystal-to-single-crystal reactions,
 illustrating their potential as a tool for complex transformations.
 The obtained hexayne carboxylates were reactive, carbon-rich siblings of typical fatty acid ester
 amphiphiles, designed to self-assemble into monolayers at the air-water interface. The film formation
 of these amphiphiles was thoroughly investigated, and a detailed molecular model of their packing
 was established by means of different spectroscopy and diffraction techniques, in combination with
 computational modeling. Our results unambiguously confirmed the presence of a well-defined
 monolayer that comprised a densely packed array of the hexayne moieties. The complete carbonization
 of the films at the air-water interface was successfully accomplished by cross-linking of the hexayne
 layer through UV irradiation at room temperature. The furnished carbon microstructure was found
 to resemble that of reduced graphene oxide or amorphous carbon materials otherwise obtained
 at annealing temperatures beyond 800°C. In this way, we prepared mechanically stable and rigid,
 functionalized carbon films with a molecularly defined thickness below 2 nm and lateral dimensions
 on the order of centimeters.
000200224 6531_ $$ananostructured carbons
000200224 6531_ $$aoligoyne carboxylates
000200224 6531_ $$asingle-crystal-to-single-crystal reaction
000200224 6531_ $$asupramolecular self-assembly
000200224 6531_ $$aLangmuir films
000200224 6531_ $$aroom temperature carbonization
000200224 6531_ $$acarbon nanosheets
000200224 700__ $$0244492$$g191982$$aSchrettl, Stephen
000200224 720_2 $$aFrauenrath, Holger$$edir.$$g190315$$0244491
000200224 8564_ $$uhttps://infoscience.epfl.ch/record/200224/files/EPFL_TH6326.pdf$$zn/a$$s141117587$$yn/a
000200224 909C0 $$xU12015$$0252311$$pLMOM
000200224 909CO $$pthesis$$pthesis-bn2018$$pDOI$$ooai:infoscience.tind.io:200224$$qDOI2$$qGLOBAL_SET$$pSTI
000200224 917Z8 $$x108898
000200224 917Z8 $$x108898
000200224 918__ $$dEDMX$$cIMX$$aSTI
000200224 919__ $$aLMOM
000200224 920__ $$b2014$$a2014-7-31
000200224 970__ $$a6326/THESES
000200224 973__ $$sPUBLISHED$$aEPFL
000200224 980__ $$aTHESIS